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Page0Revision RecordCourse CodeProductProduct VersionCourse Version ISSUEOWO205030RNCBSC6800V900R0131.00Developer/ModifierTimeApproverNew/UpdateLiang Jie2011.4G/U TeamNewDont Print This PageCopyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission WCDMA RAN Call Drop KPI and Related Counterswww.huawei.comCopyright 2008 Huawei Technologies Co., Ltd. All rights reserved. Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission Page2ObjectivesUpon completion of this course, you will be able to:Describe call drop counter systemKnow how to calculate call drop KPI

Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission Page3ContentsDefinition Of a Call DropTypical Call Drop KPI and Related CountersCounters Indicating the Call Drop Reason

Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission How to Define Call Drop?Normally CN will trigger release procedure after a service is over.For release triggered by RNC, if the release reason is one of the following, it is not defined as call drop.User inactivityUE generated signaling connection releaseIf RNC triggers release procedure but the reason is not one of the previous two, it is defined as call drop.Page4Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. The scenario for User inactivity:If a user with PS service has no data transmission after a certain timer expires (this timer is set by RNC), RNC can send signaling IU RELEASE REQUEST to CN to release the service. This is not considered as call drop.The scenario for UE generated signaling connection release Some type of UE can release signaling connection automatically be sending signaling SIGNALLING CONNECTION RELEASE INDICATION to RNC, then RNC will send signaling IU RELEASE REQUEST to CN to release the service. This is not considered as call drop neither.

WCDMA RAN Call Drop KPI and Relative CountersP-4Confidential Information of Huawei. No Spreading Without Permission Procedure for Normal ReleaseTwo scenario for normal release:Page5

Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersP-5Confidential Information of Huawei. No Spreading Without Permission Procedure for Call DropIf RNC triggers release but the reason is not user inactivity or UE generated signaling connection release, it is considered as call drop.Page6

Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersP-6Confidential Information of Huawei. No Spreading Without Permission Page7Call Drop RatioCall drop ratio in Statistic:

RNC KPIs (Average Value during N days)All ServiceCDRCS AMR Call Drop Ratio [%]0.48%VP Call Drop Ratio [%]0.92%PS Service Drop Ratio [%]0.34%HSDPACDRHSDPA Service Drop Ratio0.27%HSUPACDRHSUPA Service Drop Ratio0.29%

Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission CDR: call drop ratioPage8ContentsDefinition Of a Call DropTypical Call Drop KPI and Related CountersCounters Indicating the Call Drop Reason

Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission Page9CS Service Drop RatioThis KPI can be used to evaluate the call drop ratio of the CS service in an RNC or a cluster.KPI nameCS Service Drop RatioMeasurement ScopeCELLFormulaCS Service Drop Ratio=(CS RAB Abnormal Release/CS RAB Release)*100%Associated CountersCS Service Drop Ratio=[VS.RAB.AbnormRel.CS/(VS.RAB.AbnormRel.CS+VS.RAB.NormRel.CS)]*100%NotesThe RNC level KPIs is calculated by aggregating all the cell counters.Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission Page10Related CountersVS.RAB.AbnormRel.CS (ID: 67179778)Number of CS RABs abnormally released for cell VS.RAB.NormRel.CS (ID: 67179779)Number of CS RABs normally released for cellCopyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission Page11AMR Call Drop RatioThis KPI can be used to evaluate the call drop ratio of the AMR service in an RNC or a cluster.KPI nameAMR Call Drop RatioMeasurement ScopeCELLFormulaAMR Call Drop Ratio=(AMR RAB Abnormal Release/AMR RAB Release)*100%Associated CountersAMR Call Drop Ratio=[VS.RAB.AbnormRel.AMR/(VS.RAB.AbnormRel.AMR+VS.RAB.NormRel.AMR)]*100%NotesThe RNC level KPIs is calculated by aggregating all the cell counters.Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission Page12Related CountersVS.RAB.AbnormRel.AMR (ID: 67180082)Number of CS AMR RABs abnormally released for cellVS.RAB.NormRel.AMR (ID: 67190518)Number of CS AMR RABs normally released for cell(not including WB-AMR)Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission Page13VP Call Drop RatioThis KPI can be used to evaluate the call drop ratio of the VP service in an RNC or a cluster.KPI nameVP Call Drop RatioMeasurement ScopeCELLFormulaVP Call Drop Ratio=(VP RAB Abnormal Release/VP RAB Release)*100%Associated CountersVP Call Drop Ratio=[VS.RAB.AbnormRel.CS64/(VS.RAB.AbnormRel.CS64+VS.RAB.NormRel.CS64)]*100%NotesThe RNC level KPIs is calculated by aggregating all the cell counters.Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission VP: video phonePage14Related CountersVS.RAB.AbnormRel.CS64 (ID: 67180083)Number of CS conversational 64kbit/s RABs abnormally released for cellVS.RAB.NormRel.CS64 (ID: 67191786)Number of CS 64 kbit/s conversational RABs normally released for cellCopyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission Page15PS Service Drop Ratio (RNC)This KPI can be used to evaluate the call drop ratio of all PS services in an RNC.KPI namePS Service Drop Ratio (RNC)Measurement ScopeRNCFormulaPS Service Drop Ratio (RNC)=(PS RAB Abnormal Release/PS RAB Release)*100%Associated CountersPS Service Drop Ratio (RNC)=[VS.RAB.AbnormRel.PS.RNC/(VS.RAB.AbnormRel.PS.RNC+ VS.RAB.NormRel.PS.RNC)]*100%Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission Page16Related CountersVS.RAB.AbnormRel.PS.RNC (ID: 67174964)Number of PS RABs abnormally released for RNC VS.RAB.NormRel.PS.RNC (ID: 67174966)Number of PS RABs normally released for RNCCopyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission Page17PS Service Drop Ratio (Cell)This KPI can be used to evaluate the call drop ratio of all PS services in a cluster.KPI namePS Service Drop Ratio (Cell)Measurement ScopeCELLFormulaPS Service Drop Ratio (Cell)=(PS RAB Abnormal Release/PS RAB Release)*100%Associated CountersPS Service Drop Ratio=[VS.RAB.AbnormRel.PS/(VS.RAB.AbnormRel.PS+ VS.RAB.NormRel.PS)]*100%Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission Page18Related CountersVS.RAB.AbnormRel.PS (ID: 67179781)Number of PS RABs abnormally released for cell VS.RAB.NormRel.PS (ID: 67179782)Number of PS RABs normally released for cellCopyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission Page19PS R99 Service Drop RatioThis KPI can be used to evaluate the call drop ratio of all PS R99 services in a cluster.KPI namePS R99 Service Drop RatioMeasurement ScopeCELLFormulaPS R99 Service Drop Ratio=(PS R99 RAB Abnormal Release/PS R99 RAB Release)*100%Associated CountersPS R99 Service Drop Ratio=[VS.RAB.AbnormRel.PSR99/(VS.RAB.AbnormRel.PSR99+ VS.RAB.NormRel.PSR99)]*100%Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission Page20Related CountersVS.RAB.AbnormRel.PSR99 (ID: 73403806)Number of PS R99 RABs abnormally released for cell(including RF failure) VS.RAB.NormRel.PSR99 (ID: 73403807)Number of PS R99 RAB successfully released for cellCopyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission Page21HSDPA Service Drop RatioThis KPI can be used to evaluate the call drop ratio of the PS service carried by HSDPA in an RNC or a cluster.KPI nameHSDPA Service Drop RatioMeasurement ScopeCELLFormulaHSDPA Service Drop Ratio=(HSDPA_RABAbnormalRelease/HSDPA_RABRelease)*100%Associated CountersHSDPA Service Drop Ratio=[(VS.HSDPA.RAB.AbnormRel)/(VS.HSDPA.RAB.AbnormRel+VS.HSDPA.RAB.NormRel+VS.HSDPA.H2D.Succ+VS.HSDPA.H2F.Succ+VS.HSDPA.HHO.H2D.SuccOutIntraFreq+VS.HSDPA.HHO.H2D.SuccOutInterFreq)]*100%NotesThe RNC level KPIs is calculated by aggregating all the cell counters.The successful channel transition is considered as normal HS-DSCH release ( including transitions due to mobility).Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission Why VS.HSDPA.H2D.Succ+VS.HSDPA.H2F.Succ+VS.HSDPA.HHO.H2D.SuccOutIntraFreq+VS.HSDPA.HHO.H2D.SuccOutInterFreq is added in the denominator to calculate the HSDPA service drop ratio?If one user switch from HS-DSCH to other channel types due to some reason (mobility e.g.), it should be consider as a normal HS-DSCH release (refer to second item in Notes).Page22Related CountersVS.HSDPA.RAB.AbnormRel (ID: 67191162)VS.HSDPA.RAB.NormRel (ID: 67191164)VS.HSDPA.H2D.Succ (ID: 67189832)VS.HSDPA.H2F.Succ (ID: 67189833)VS.HSDPA.HHO.H2D.SuccOutIntraFreq (ID: 67191158)VS.HSDPA.HHO.H2D.SuccOutInterFreq (ID: 67191160)Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission VS.HSDPA.RAB.AbnormRelNumber of HSDPA RABs abnormal released for cellVS.HSDPA.RAB.NormRelNumber of HSDPA RABs normal released for cellVS.HSDPA.H2D.SuccNumber of successful handovers from HS-DSCH to DCH for cellVS.HSDPA.H2F.SuccNumber of successful handovers from HS-DSCH to CCH for cellVS.HSDPA.HHO.H2D.SuccOutIntraFreqNumber of successful Intra-Frequency H2D hard handovers for cellVS.HSDPA.HHO.H2D.SuccOutInterFreqNumber of successful Inter-Frequency H2D hard handovers for cell

Page23HSUPA Service Drop RatioThis KPI can be used to evaluate the call drop ratio of the PS service carried by HSUPA in an RNC or a cluster.KPI nameHSUPA Service Drop RatioMeasurement ScopeCELLFormulaHSUPA Service Drop Ratio=(HSUPA_RAB Abnormal Release/HSUPA_RABRelease)*100%Associated CountersHSUPA Service Drop Ratio=[(VS.HSUPA.RAB.AbnormRel)/(VS.HSUPA.RAB.AbnormRel+VS.HSUPA.RAB.NormRel+VS.HSUPA.E2D.Succ+VS.HSUPA.E2F.Succ+VS.HSUPA.HHO.E2D.SuccOutIntraFreq+VS.HSUPA.HHO.E2D.SuccOutInterFreq)]*100%NotesThe RNC level KPIs is calculated by aggregating all the cell counters.The successful channel transition is considered as normal E-DCH release ( including transitions due to mobility).Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission Why VS.HSUPA.E2D.Succ+VS.HSUPA.E2F.Succ+VS.HSUPA.HHO.E2D.SuccOutIntraFreq+VS.HSUPA.HHO.E2D.SuccOutInterFreq is added in the denominator to calculate the HSUPA service drop ratio?If one user switch from E-DCH to other channel types due to some reason (mobility e.g.), it should be consider as a normal E-DCH release (refer to second item in Notes).Page24Related CountersVS.HSUPA.RAB.AbnormRel (ID: 67192364)VS.HSUPA.RAB.NormRel (ID: 67192365)VS.HSUPA.E2D.Succ (ID: 67192470)VS.HSUPA.E2F.Succ (ID: 67192481)VS.HSUPA.HHO.E2D.SuccOutIntraFreq (ID: 67192472)VS.HSUPA.HHO.E2D.SuccOutInterFreq (ID: 67192474)Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission VS.HSUPA.RAB.AbnormRelNumber of HSUPA RABs abnormal released for cellVS.HSUPA.RAB.NormRelNumber of HSUPA RABs normal released for cellVS.HSUPA.E2D.SuccNumber of successful handovers from E-DCH to DCH for cellVS.HSUPA.E2F.SuccNumber of successful handovers from E-DCH to CCH for cellVS.HSUPA.HHO.E2D.SuccOutIntraFreqNumber of successful Intra-Frequency E2D hard handovers for cellVS.HSUPA.HHO.E2D.SuccOutInterFreqNumber of successful Inter-Frequency E2D hard handovers for cellPage25ContentsDefinition Of a Call DropTypical Call Drop KPI and Related CountersCounters Indicating the Call Drop Reason

Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission How to Get the Call Drop Reason?If RNC triggers release request abnormally, it will tell CN the reason of release request and then the corresponding counter will be triggered. So these counters can be used to analyze the call drop reason.Page26

Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. If the call drop ratio is high, we need to find the reason. Some counters can indicate the reason of call drop.WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission Number of Released RABs due to RF cause (RNC Level)VS.RAB.AbnormRel.CS.RF.RNC (ID: 67174954)Number of CS RABs Abnormally Released due to RF cause for RNCVS.RAB.AbnormRel.PS.RF.RNC (ID: 67174955)Number of PS RABs Abnormally Released due to RF cause for RNCPage27Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. Normally RF (radio frequency) problem is the main reason of call drop in real network such as bad coverage or handover failure.WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission CS RABs Abnormally Released Triggered Due to Different Causes (Cell Level)VS.RAB.AbnormRel.CS.IuAAL2 (ID: 67180080)VS.RAB.AbnormRel.CS.RF (ID: 67179777)VS.RAB.AbnormRel.CS.OM (ID: 67179767)VS.RAB.AbnormRel.CS.Preempt (ID: 67179769)VS.RAB.AbnormRel.CS.UTRANgen (ID: 67179768)VS.RAB.AbnormRel.CS.OLC (ID: 67190841)Page28Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. VS.RAB.AbnormRel.CS.IuAAL2Number of CS RABs Abnormally Released for Cell Due to Iu Interface AAL2 Link FailureThis counter is triggered when RNC finds the AAL2 path is abnormal. Maybe it is the problem of Iu-CS transmission.VS.RAB.AbnormRel.CS.RFNumber of CS RABs Abnormally Released Due to RF for CellSome RF problems will trigger this counter such as bad coverage, handover failure, interference and etc. Normally RF problem is the main reason of call drop in real network.VS.RAB.AbnormRel.CS.OMNumber of CS RAB Release Requests for Cell Due to O&M InterventionIf RAB is release by O&M intervention (For example RAB is released by MML command), this counter will be triggered. Normally this is not the main reason of call drop in real network.VS.RAB.AbnormRel.CS.PreemptNumber of CS RAB Release Attempts for Cell Due to RAB PreemptionDuring access control procedure if system resource is limited and preemption function is enabled, a user with higher priority can preempt a user with lower priority. Then this counter will be triggered.VS.RAB.AbnormRel.CS.UTRANgenNumber of CS RAB Abnormal Releases Triggered by RNC for Cell Due to UTRAN CauseIf RAB is released because of UTRAN problem, this counter will be triggered. If this counter has high value, more detailed information need to be collected and analyzed.VS.RAB.AbnormRel.CS.OLCNumber of CS Domain RABs Released Due to Congestion for CellIf the system load is very high and over load control function is enabled, RNC can release some RAB to reduce the load. Then this counter will be triggered. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission CS RABs Abnormally Released Due to Different RF Causes (Cell Level)VS.RAB.AbnormRel.CS.RF.ULSync (ID: 67189568)Number of CS RABs Abnormally Released Due to Uplink Synchronization Failure for CellVS.RAB.AbnormRel.CS.RF.UuNoReply (ID: 67190505)Number of CS RABs Abnormally Released Due to Failure in the Radio Interface Procedure for CellVS.RAB.AbnormRel.CS.RF.SRBReset (ID: 67180077)Number of CS RABs Abnormally Released Due to Signaling RLC Reset for CellPage29Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. Normally RF problem is the main reason of call drop. More sub counters can be used to analyze the detailed RF reason of call drop. To find the exact reason maybe more detailed information such as drive test result and signaling trace result need to be collected.VS.RAB.AbnormRel.CS.RF.ULSyncIf NodeB loses the UL synchronization of the UE during service, the RAB will be released and this counter will be triggered. Bad coverage or missing neighboring cell configuration can triggered this counter.VS.RAB.AbnormRel.CS.RF.UuNoReplyIf UE can not respond to the signaling from RNC during service, the RAB will be release and this counter will be triggered. Bad coverage can trigger this counter.VS.RAB.AbnormRel.CS.RF.SRBResetIf RNC sends signaling to UE repeat but UE can not send a ACK response, RNC will reset RLC layer. Then call drop will happen and this counter will be triggered. Bad coverage or interference can trigger this counter.

WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission Counter RelationshipPage30CounterSub CounterSub CounterVS.RAB.AbnormRel.CSVS.RAB.AbnormRel.CS.OMVS.RAB.AbnormRel.CS.PreemptVS.RAB.AbnormRel.CS.UTRANgenVS.RAB.AbnormRel.CS.IuAAL2VS.RAB.AbnormRel.CS.OLCVS.RAB.AbnormRel.CS.RFVS.RAB.AbnormRel.CS.RF.ULSyncVS.RAB.AbnormRel.CS.RF.UuNoReplyVS.RAB.AbnormRel.CS.RF.SRBResetCopyright 2008 Huawei Technologies Co., Ltd. All rights reserved. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission PS RABs Abnormally Released Triggered Due to Different Causes (Cell Level)VS.RAB.AbnormRel.PS.GTPULoss (ID: 67180081)VS.RAB.AbnormRel.PS.RF (ID: 67179780)VS.RAB.AbnormRel.PS.OM (ID: 67180074)VS.RAB.AbnormRel.PS.Preempt (ID: 67180076)VS.RAB.AbnormRel.PS.OLC (ID: 67190840)Page31Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. VS.RAB.AbnormRel.PS.GTPULossNumber of PS RABs Abnormally Released for Cell Due to GTPU FailureThis counter is triggered when RNC finds the GTPU in Iu-PS user plane is abnormal. Maybe it is the problem of Iu-PS transmission.VS.RAB.AbnormRel.PS.RFNumber of PS RABs Abnormally Released Due to RF for CellSome RF problems will trigger this counter such as bad coverage, handover failure, interference and etc. Normally RF problem is the main reason of call drop in real network.VS.RAB.AbnormRel.PS.OMNumber of PS RAB Release Requests for Cell Due to O&M InterventionIf RAB is release by O&M intervention (For example RAB is released by MML command), this counter will be triggered. Normally this is not the main reason of call drop in real network.VS.RAB.AbnormRel.PS.PreemptNumber of PS RAB Release Attempts for Cell Due to RAB PreemptionDuring access control procedure if system resource is limited and preemption function is enabled, a user with higher priority can preempt a user with lower priority. Then this counter will be triggered.VS.RAB.AbnormRel.PS.OLCNumber of PS Domain RABs Released Due to Congestion for CellIf the system load is very high and over load control function is enabled, RNC can release some RAB to reduce the load. Then this counter will be triggered. WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission PS RABs Abnormally Released Due to Different RF Causes (Cell Level)VS.RAB.AbnormRel.PS.RF.ULSync (ID: 67189572)Number of PS RABs Abnormally Released Due to Uplink Synchronization Failure for CellVS.RAB.AbnormRel.PS.RF.UuNoReply (ID: 67190506)Number of PS RABs Abnormally Released Due to Failure in the Radio Interface Procedure for CellVS.RAB.AbnormRel.PS.RF.SRBReset (ID: 67180078)Number of PS RABs Abnormally Released Due to Signaling RLC Reset for CellVS.RAB.AbnormRel.PS.RF.TRBReset (ID: 67180079)Number of PS RABs Abnormally Released Due to Traffic RLC Reset for CellPage32Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. Normally RF problem is the main reason of call drop. More sub counters can be used to analyze the detailed RF reason of call drop. To find the exact reason maybe more detailed information such as drive test result and signaling trace result need to be collected.VS.RAB.AbnormRel.PS.RF.ULSyncIf NodeB loses the UL synchronization of the UE during service, the RAB will be released and this counter will be triggered. Bad coverage or missing neighboring cell configuration can triggered this counter.VS.RAB.AbnormRel.PS.RF.UuNoReplyIf UE can not respond to the signaling from RNC during service, the RAB will be release and this counter will be triggered. Bad coverage can trigger this counter.VS.RAB.AbnormRel.PS.RF.SRBResetIf RNC sends signaling to UE repeat but UE can not send a ACK response, RNC will reset RLC layer. Then call drop will happen and this counter will be triggered. Bad coverage or interference can trigger this counter.VS.RAB.AbnormRel.PS.RF.TRBResetIf RNC sends PS data to UE repeat but UE can not send a ACK response, RNC will reset RLC layer. Then call drop will happen and this counter will be triggered. Bad coverage or interference can trigger this counter.

WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission Counter RelationshipPage33CounterSub CounterSub CounterVS.RAB.AbnormRel.PSVS.RAB.AbnormRel.PS.OMVS.RAB.AbnormRel.PS.PreemptVS.RAB.AbnormRel.PS.GTPULossVS.RAB.AbnormRel.PS.OLCVS.RAB.AbnormRel.PS.RFVS.RAB.AbnormRel.PS.RF.ULSyncVS.RAB.AbnormRel.PS.RF.UuNoReplyVS.RAB.AbnormRel.PS.RF.SRBResetVS.RAB.AbnormRel.PS.RF.TRBResetCopyright 2008 Huawei Technologies Co., Ltd. All rights reserved. A Example of CS RABs Abnormally Released Due to Different CausesVS.RAB.AbnormRel.CS.OMVS.RAB.AbnormRel.CS.PreemptVS.RAB.AbnormRel.CS.UTRANgenVS.RAB.AbnormRel.CS.RF.SRBResetVS.RAB.AbnormRel.CS.RF.ULSyncVS.RAB.AbnormRel.CS.RF.UuNoReplyVS.RAB.AbnormRel.CS.IuAAL2Cell 10001410370Cell 2000128210Cell 30001111140Cell 400054160Cell 500056170Cell 600075140Cell 700013140Cell 800051190Cell 900034170Cell 1000033110Page34Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. The table shows the result of CS call drop of Top 10 cells in one month. It is from a real network.In the example we can see that most of the CS call drops in the network are caused by RF problems.

WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission A Example of PS RABs Abnormally Released Due to Different CausesVS.RAB.AbnormRel.PS.OMVS.RAB.AbnormRel.PS.PreemptVS.RAB.AbnormRel.PS.RF.SRBReset + VS.RAB.AbnormRel.PS.RF.SRBResetVS.RAB.AbnormRel.PS.RF.ULSyncVS.RAB.AbnormRel.PS.RF.UuNoReplyVS.RAB.AbnormRel.PS.GTUPLossCell 1006792485150Cell 200437816670Cell 3003942953710Cell 4003683063190Cell 5003562143380Cell 600379983200Cell 700326793480Cell 800302632670Cell 900180206000Cell 10003291131880Page35Copyright 2008 Huawei Technologies Co., Ltd. All rights reserved. The table shows the result of PS call drop of Top 10 cells in one month. It is from a real network.In the example we can see that most of the PS call drops in the network are caused by RF problems.

WCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission Thank youwww.huawei.comWCDMA RAN Call Drop KPI and Relative CountersConfidential Information of Huawei. No Spreading Without Permission CN

RNC

IU Release Command

IU Release Complete

Scenario 1: CN triggers release.

CN

RNC

IU Release Command

IU Release Complete

IU Release Request orRAB Release Request

Scenario 2: RNC triggers release but the reason is user inactivity or UE generated signaling connection release.

CN

RNC

IU Release Command

IU Release Complete

IU Release Request orRAB Release Request

CN

RNC

IU Release Command

IU Release Complete

IU Release Request orRAB Release Request

In this signaling, RNC tells CN the reason of release request. Different counters will be triggered by corresponding reason. These counters can be used to analyze the reason of call drop.